/*
 * Copyright (C) 2007 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;

import java.io.Serializable;

/**
 * An ordering that uses the natural order of the string representation of the values.
 */
@GwtCompatible(serializable = true)
@ElementTypesAreNonnullByDefault
final class UsingToStringOrdering extends Ordering<Object> implements Serializable
{
    static final UsingToStringOrdering INSTANCE = new UsingToStringOrdering();

    @Override
    public int compare(Object left, Object right)
    {
        return left.toString().compareTo(right.toString());
    }

    // preserve singleton-ness, so equals() and hashCode() work correctly
    private Object readResolve()
    {
        return INSTANCE;
    }

    @Override
    public String toString()
    {
        return "Ordering.usingToString()";
    }

    private UsingToStringOrdering()
    {
    }

    private static final long serialVersionUID = 0;
}
